JPS6016470B2 - Improved molding compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to an improved molding compound.

More specifically, the present invention provides a thermosetting polyester resin by incorporating into a thermosetting polyester resin a thermoplastic composition prepared by polymerizing at least one monomer and at least two unsaturated polymeric elastomers. Concerning degeneration. Thermosetting resin prepolymers which are unsaturated polyesters and which cross-link in the thermosetting state during curing are known.

When thermoset polyesters are used in molded sheets or bulk molding compounds, the molded articles usually shrink and dent and have dull surfaces. To obviate at least some of the above difficulties, it is common to combine thermoset polyester resins with at least one thermoplastic resin.

The thermoset and thermoplastic resins are mixed in syrup form and the resin syrup combination is blended with fillers, cross-linking agents, and gelling agents to form molded article compositions. This composition, when molded, yields a molded article containing a thermosetting polyester resin as a continuous phase with a dispersed thermoplastic resin. The present invention provides novel thermoplastic compositions that are incorporated into thermoset polyester resins to reduce shrinkage and improve the surface properties of molded articles.

According to the present invention, the thermoplastic composition is composed of a thermoplastic composition prepared by polymerizing at least one monomer and first and second unsaturated elastomers, a moldable polyester, and a polymerization-reactive monomer. A moldable composition is provided.

Further, according to the present invention, at least one monomer and a first
and a second unsaturated elastomeric polymer, and a second unsaturated elastomeric polymer is provided.

provided that the thermoplastic composition is present in an amount sufficient to modify at least one property of the molded thermoset. Unsaturated polyesters themselves are well known in the art, as are their methods of manufacture.

The above polyester can be synthesized by condensing Q.8-ethylenically unsaturated dicarboxylic acid, its anhydride, or a mixture thereof with a dihydric alcohol or a dihydric alcohol mixture. Here, the term "dicarboxylic acid" is intended to include the anhydride of the corresponding acid. Examples of preferred unsaturated dicarboxylic acids are maleic acid or fumaric acid. The carboxylic acid present in the polyester of the present invention is preferably of an unsaturated type. Dihydric alcohols useful in this polyester synthesis include propylene glycol, dibropylene glycol, diethylene glycol, 1,3-butanediol, and the like, and mixtures thereof. The unsaturated thermosetting polyesters that can be used in the present invention are synthesized under known conditions including temperatures within the range of about 90 to 4000 F and include materials such as toluhydroquinone, hydroquinone, hydroquinone methyl ether, m-dinitrobenzene, etc. Use to stop the reaction.

Preferably, the polymerization is terminated at an acid number of about 100 or less, with an acid number of about 30 being particularly suitable. The monomer used in the present invention has at least one ethylene-reactive group per molecule.
A liquid monomer or monomer mixture with C=C<.

This monomeric liquid material must be copolymerizable with the unsaturated polyester and develop a crosslinked or thermoset structure with the polyester. This monomer is required to act as a solvent for unsaturated polyesters and thermoplastic polymers over a wide range of concentrations. Examples of suitable monomers are styrene, vinyltoluene, methyl methacrylate, butyl methacrylate, etc., and mixtures thereof. The unsaturated thermoplastic compositions of the present invention are synthesized using conventional polymerization techniques using the ingredients as described below.

Preferably, the polymerization temperature is in the range of about 100 to about 2000 F and the reaction is initiated by an initiator such as penzoyl peroxide, azobis, (isobutyronitrile), and the like.
50% as indicated by the solids content of the reaction mixture
Preferably, the reaction is stopped at about 30-40% conversion. Reagents used for reaction termination include toluhydroquinone, hydroquinone, hydroquinone methyl ether, and the like.
As will be clear from the following description, the methods used to synthesize thermoplastic polymers that are incorporated into polyester resins are:
This is the method by which a large number of graft polymers are made.

This large number of polymers, used in combination and in their entirety, is collectively referred to herein as a "thermoplastic composition."
The polymerization reaction mixture contains up to about 5% by weight of a functional or polyfunctional organic acid or anhydride containing one double bond per molecule and reactive with the monomer, and from about 43,000 to about 380,000 from about 0.1 to about 7.5% by weight of a raw unsaturated elastomeric polymer having a molecular weight within the range of about 500% by weight;
from about 0.1 to about 15% by weight of a raw unsaturated elastomeric polymer having a molecular weight in the range of from about 40,000, up to about 5% by weight of comonomers, and from 15 to about 15% by weight of at least one monomer.
The thermoplastic composition of the present invention can be synthesized by using about 92% by weight.

Up to about 3% by weight of the organic acid and about 6% by weight of the organic acid are added to the polymerization reaction mixture.
from about 0.5% to about 5% by weight of the raw unsaturated elastomeric polymer having a molecular weight within the range of from about 0,000 to about 20,000; Preferred thermoplastic compositions of the present invention can be synthesized by using up to about 9% by weight of the comonomer, up to about 4% by weight of the comonomer, and from about 35% to about 9% by weight of at least one monomer. The most preferred embodiment of the invention uses acrylic acid, a styrene-butadiene rubber with a molecular weight of about 100,000, a hydroxy-terminated polybutadiene with a molecular weight of about 1,000, and styrene to form the thermoplastic composition.

Since the preferred monomer is styrene, the invention will be described in terms of styrene (without the intent to limit the invention).

The thermoplastic composition can contain up to 5% by weight of comonomers that affect pigmentability, film adhesion, surface gloss, etc., the comonomers being methyl methacrylate, methyl methacrylate,
Including ethyl acrylate, acrylonitrile, pinylpyridine, etc., and mixtures thereof.

The first elastomeric unsaturated polymer having a molecular weight within the range of about 43,000 to about 380,000 is soluble in the monomers used and contains greater than 1% by weight of the gene.

Suitable unsaturated elastomeric polymers include styrene-butadiene rubber, polybutadiene, polyisoprene, polychloroprene, mixtures of the above polymers, copolymers of the above polymers with styrene and other monomers. 500 to about 4000
The second elastomeric unsaturated polymer having a molecular weight in the range of 0 is soluble in the monomers used and contains over 1% by weight of Jen.

Suitable unsaturated polymers include styrene-butadiene rubber, polybutadiene, polyisoprene, polychloroprene, mixtures of the above polymers, copolymers of the above polymers with styrene and other monomers. The term "molecular weight" as used herein refers to weight average molecular weight.

The thermoplastic composition and polyester thermoset can be blended in a weight ratio of about 1:1 to about 1:10, respectively, on a styrene-free basis.

Preferably, resins are used in a range of about 1 part by weight of thermoplastic composition to about 2 to about 5 parts by weight of polyester resin.

Best results are obtained when using about 1 part by weight of thermoplastic composition to about 3 parts by weight of polyester resin. Generally, the process is carried out by forming a thermoplastic composition using a defined elastomer, the polymerization between the monomer and the elastomer being carried out to about 33% completion, and the unsaturated thermoplastic composition being present in syrup form. Sufficient monomer is present in the polymerization product so that

In the same machine, a polyester resin is prepared and diluted with monomers so that the unsaturated thermoset polyester resin is present in syrup form.

These two syrups are blended with a cross-linking agent, a gelling agent, a filler such as glass fibers, and molded under conditions that allow the polyester to cross-link and form a thermoplastic elastomer-based composition as a dispersed phase. Forming a cross-linked polyester matrix present.

The following examples demonstrate the effectiveness of thermoplastic compositions of the present invention in reducing shrinkage and improving surface gloss of cross-bonded and molded polyester resins.

Example 1 illustrates the preparation of a representative thermosetting polyester resin syrup, in which a control thermoplastic composition and a thermoplastic made using a polymeric elastomer were individually blended and then molded. be.

However, the present invention is applicable to any unsaturated polyester used in molding compounds and is not limited to the particular embodiments used for illustrative purposes. Example 2 demonstrates the preparation of a control thermoplastic syrup made from styrene and acrylic acid without the elastomeric polymer used in the process of the present invention.

Example 3 illustrates the preparation of a thermoplastic composition syrup using an elastomeric polymer according to the invention.

Example 4 illustrates the preparation of a molding compound from the thermoset polyester resin syrup of Example 1 and the thermoplastic composition syrup of Examples 2 and 3, and presents comparative data therebetween.

Example 1 A thermosetting polyester resin syrup was made from the following materials in substantially the manner described below.

All propylene glycol and 1/3 maleic anhydride were charged into a reactor, during which nitrogen was continuously sparged to produce a polyester resin syrup.

The reactor contents temperature was raised to 1900 F' and about 1/2 of the tolquinone solution was added about 4 hours after the first distillate. When the reactor contents reached an acid number of about 35, the remainder of the tolquinone solution was added. The remainder of the maleic anhydride is then added at 10 to 15% per minute while controlling the maximum temperature to 3000F.
It was added in a proportion of 100%. Then reduce the temperature of the mixture to 60 minutes 3
It was held at 10-3200F and then the temperature was increased to 4000F'.

At this point, the material in the reactor has an acid number of 29-32, and 2 parts of the reactor contents diluted with 1 part of styrene is 3500 F2.
It had a viscosity (SSU) of 1-25. Reactor contents to 3
It was cooled to 400F and diluted with styrene in an amount of 90 parts reactor contents to 1 part styrene to produce a composition that was stable for 30 minutes at 1200C before gelling.

In a separate container, add 486.4 parts by weight of styrene to rt.
- Mix 0.125 parts by weight of butylhydroquinone,
The temperature was maintained within the range of 0-14 rF. After that, polyester resin 1 made at about 3300F as described above
．． A diluted polyester syrup was prepared by adding 138 parts to the above styrene-hydroquinone mixture. This material has a viscosity of 1500-200 specific ps at 1800F, a maximum water content of about 0.0% by neck weight, and a monomer content of about 3
It was within the range of 0 to about 34% by weight. This example demonstrates the preparation of a thermosetting polyester resin syrup, which was individually blended with the thermoplastic compositions made in Examples 2 and 3 to form molded articles.

Example 2 A control thermoplastic composition syrup outside the scope of the present invention was made in the following manner.

Eight parts by weight of styrene and 1.04 parts by weight of acrylic acid were charged into a reactor, the contents of the reactor were heated to 1670F', and at this temperature 0.123 parts by weight of penzoyl peroxide was added.

The reaction was continued at about 1670F for a sufficient time to obtain a composite having a solids content of about 3 box weight percent. In this respect,
0.03 parts by weight of truhydroquinone was added and the reaction mixture was cooled. This thermoplastic composition had an acid number of 8.3 and a viscosity at room temperature of about 440 ps. Thus, a saturated thermoplastic syrup whose composition was outside the scope of the present invention was made and used as a comparison or "control" for the thermoplastic composition within the scope of the present invention prepared in Example 3. Example 3 A series of elastomers having the molecular weights defined above were combined into a thermoplastic composition syrup and then individually blended with the thermoset resin syrup made in Example 1.

Each syrup mixture was then incorporated into a molding compound by a procedure similar to Example 4. The elastomers used to make examples of the thermoplastic compositions of this invention are commercially available and are listed in Table 1.

Table 1 Phillips〒Philips Vetroleum Company Litco Alco: Alco Chemical Company S/B = Styrene-butadiene polymer Styrene, acrylic acid, and 2 having a specified molecular weight
Each thermoplastic composition was made by making a polymer from a seed elastomer.

The two elastomers were used in a total amount of about 7.3 parts by weight per 100 parts by weight of styrene, acrylic acid, and elastomer. A representative example of the above preparation is as follows, in which the styrene-ptadiene polymer and polybutadiene polymer were combined into a thermoplastic resin using the following materials and procedures.

All materials were charged to the reactor except for penzoyl peroxide and truhydroquinone.

Sprinkle the mixture with FM nitrogen to 0.05 and 1 bulb. Heated to F. Penzoyl peroxide was introduced into the reactor contents, polymerization was carried out, and fixation was measured every 3 q. When the solids content reaches a degree of conversion of 36±2%, toluhydroquinone is added to inhibit further polymerization, and styrene is added to the reactor contents to reduce the solids content of the reaction mixture to about 3%.
3% to form a thermoplastic composition syrup according to the invention. Example 4 This example shows the preparation of the final molding compound and also shows a comparison of the properties after molding using the "control" made in Example 2 and the invention made in Example 3. .

In each case, a predetermined amount of the thermoset polyester syrup made as in Example 1 was individually blended with the thermoplastic composition syrup made in Examples 2 and 3.

Each blend had the following composition. Table 2 Two syrups, benzoic acid, were blended with rt-butyl, zinc stearate, and calcium carbonate to create a smooth base.

Magnesium hydroxide was added to this paste and mixing continued for 2 minutes. The cut glass was then added and mixing continued for an additional 2.5 minutes. The mixture was then aged at room temperature for approximately 4 hours. Next, the molding pressure was about 100 psi, and the platen temperature was 27.
Each mixture was formed into 12 inch x 18 inch flat sheets using a 0-3000F range and a 2.5-3.0 minute cure cycle.

Shrinkage on cold forming of all sheets was measured. Shrinkage data for each of the elastomer-modified thermoset polyester molding compounds and the specific formulation used in each case are shown in Table 3.

In each case, shrinkage was compared to a "control" thermoplastic modified molding compound.

Table 3 It can be seen from the above data that incorporation of elastomer-based thermoplastic compositions into thermoset resins results in molding compounds with reduced shrinkage during molding compared to controls without elastomers.

In particular, penzoyl peroxide is used as a polymerization initiator to create a graft copolymer that combines elastomers. When carrying out polymerization within the range of about 33% to about 37%, about 83% of each
It has been found that combinations of styrene-butadiene copolymers and polybutadiene having molecular weights of 0.000 and 500 to 1000 are particularly suitable for use in the present invention. It will be obvious to those skilled in the art that the present invention is susceptible to various modifications.

It should be understood that such variations are, of course, within the scope of the invention. The embodiments and related matters of the present invention are as follows. [1) The thermoplastic composition is made from about 0.1 to about 7.5% by weight of the first unsaturated elastomeric polymer and about 0.1 to about 15% by weight of the second unsaturated elastomeric polymer. Compositions as claimed.

■ About 0.5 to about 5% by weight of an unsaturated elastomeric polymer having a molecular weight in the range of about 60,000 to about 200,000.
and from about 0.5% to about 9% by weight of an unsaturated elastomeric polymer having a molecular weight within the range of about 500 to about 40,000. '3' The first unsaturated elastomeric polymer is about 10
The composition of claim 1, wherein the composition is a styrene-butadiene rubber having a molecular weight of about 1,000, and the second elastomeric polymer is polybutadiene with hydroxy end groups having a molecular weight of about 1,000.

'4} About 1:1 to about 1:10 on a monomer-free basis
The composition according to the claims, wherein the thermoplastic composition and the thermosetting resin are blended in a weight ratio of .

'5) The composition of claim, wherein the thermoplastic composition and the thermosetting resin are blended in a weight ratio of about 1:2 to about 1:5 on a monomer-free basis.

(The composition of claim 1, wherein the thermoplastic composition and the thermosetting resin are blended in a weight ratio of about 1 to about 3 on a 6' monomer-free basis.)

'7} The first elastomer polymer is a styrene-butadiene copolymer having a molecular weight of about 83,000,
The composition of claim 1, wherein the second elastomeric polymer is polybutadiene having a molecular weight of about 500-1000. ■ Claims using the first unsaturated elastomeric polymer in an amount within the range of about 0.1 to about 7.5% by weight of the polymerizable mixture comprising the monomer and the first and second elastomers. The composition described in.

(9} Claims using the second unsaturated elastomer polymer in an amount within the range of about 0.1 to about 15% by weight of the polymerizable mixture of monomer and the first and second elastomers. 00 The thermoplastic composition in a polymerization mixture containing up to about 3% by weight of a monofunctional or polyfunctional organic acid or anhydride containing one reactive double bond per molecule. A claimed composition for making a product. (11) A patent for making the thermoplastic composition using up to 4% by weight of a comonomer selected from the group consisting of methyl methacrylate, ethyl acrylate, acrylonitrile, and vinylpyridine. Compositions as claimed.

(1) each of said first and second unsaturated elastomer contains at least 1% by weight of Jen, up to about 3% by weight of acrylic acid and about 7.5% by weight of said first unsaturated elastomer polymer; and about 15% by weight of the second unsaturated elastomer and about 72 to about 73% by weight of the monomer to form the composition.

(13) The composition according to the claims, wherein the thermosetting resin and the thermoplastic composition are brought into contact with and mixed with a cross-linking binder and a gelling agent.

(The composition according to the claims, which contains a single fiber glass fiber.

(15) The moldable composition comprises about 16% by weight of the thermosetting polyester resin as a syrup containing about 33% solids.
and about 11% by weight of the thermoplastic composition as a syrup containing about 33% solids, and about 30% by weight glass.

(16) [a- Unsaturated thermosetting polyester resin,
a polymerizable reactive monomer, at least one monomer and a first
and an unsaturated thermoplastic composition comprising the reaction product with a second unsaturated elastomeric polymer, forming a mixture comprising: a second unsaturated elastomeric polymer; A method for producing a shaped composition, characterized in that said thermoplastic composition is present in said mixture in an amount of said thermoplastic composition, and [b} said mixture is shaped.

(17) The first elastomer polymer has a molecular weight of about 43,000 to
The method of paragraph (16) above, wherein the second elastomeric polymer has a molecular weight within the range of about 380,000 and the second elastomeric polymer has a molecular weight within the range of about 500 to about 40,000.

Claims (1)

[Claims] 1 (a) an unsaturated thermosetting polyester resin; (b)
a first unsaturated elastomeric polymer having a polymerizable reactive monomer and (c) at least one monomer and a molecular weight within the range of about 43,000 to about 380,000 and a molecular weight within the range of about 500 to about 40,000. an unsaturated thermoplastic composition comprising the reaction product of a second unsaturated elastomeric polymer having a composition, in a weight ratio of from about 1:1 to about 1:10 on a monomer-free basis when molded. A moldable composition comprising the thermoplastic composition and the thermosetting composition.